Genes that are specifically regulated during lymphangiogenesis as compared to blood vessel angiogenesis during tumorigenesis will be identified and characterized. Transgenic mice will be generated that express angiogenic and lymphangiogenic factors in normal tissue and during tumour development. Normal tissue or tumour tissue with ongoing lymphangiogenesis and/or angiogenesis will be used to perform expression-profiling analyses by gene array technology. Peptide and protein domain phage display using metastatic vs. non-metastatic tumor cells as targets to discover proteins associated with the metastases.